Question: $ { {3} \times \left[\begin{array}{rr}{-2} & {-2} \\ {-2} & {3} \\ {2} & {-1}\end{array}\right] = {?} } $
Explanation: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rr}{3}\times{-2} & {3}\times{-2} \\ {3}\times{-2} & {3}\times{3} \\ {3}\times{2} & {3}\times{-1}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rr}{-6} & {-6} \\ {-6} & {9} \\ {6} & {-3}\end{array}\right]}$